Interpretive Summary: The spined soldier bug is a beneficial insect predator native to North America, and is commonly found feeding upon eggs, larvae and adults of many agricultural and forestry pest insects. Several artificial diets have been developed for rearing this beneficial insect. However, thus far all diets have been insufficient to support normal growth rates and production of offspring. The potential outcome of decreased growth rate and fewer offspring is a cost increase in production and rearing of the beneficial insect. A cost increase in production would cause a decrease in the economic feasibility of using those diets to mass rear this insect for use as a biological control agent. This study showed that when fed a new diet containing plant, beef liver and whole egg, the growth rate and number of progeny of the spined soldier bug remained lower than when fed a natural host insect. However, the cost of diet was sufficiently lower than the cost of rearing natural host insect such that the estimate of the actual cost of rearing on the artificial diet was approximately the same as the cost of rearing on the natural host insect. This is a significant achievement in the effort to develop cost-effective artificial diets for the mass-rearing of beneficial predatory bugs, and demonstrates that the use of an artificial diet can be a cost effective method to rear the spined soldier bug.

Technical Abstract:
The impact of a zoophytophagous, insect-free artificial diet upon the developmental rate, life table parameters, and fertility table parameters was examined over eleven consecutive generations for domesticated and wild colonies of Podisus maculiventris (Say) (Heteroptera: Pentatomidae). This study showed that the developmental time, pre-oviposition period, fecundity, and nymphal survival improved in the domestic colony when fed a insect-free artificial diet for eleven consecutive generations, but remained relatively constant for the wild colony, as did reproductive rate and intrinsic rate of increase. Although, after eleven generations of adaptation to an artificial diet feeding regime, all reproductive and fertility table parameters were still significantly lower than when fed on T.ni larvae as the natural prey, the realized cost of rearing either colony on the artificial diet approached 1.2 times the cost of rearing these insects on a natural prey. This is a significant achievement in the effor to develop cost-effective artificial diets for the mass-rearing of beneficial pentatomids, and has positive implications for the use of one artificial diet to efficiently rear several beneficial insects.